diff options
Diffstat (limited to 'arch/x86/mm/init_32.c')
| -rw-r--r-- | arch/x86/mm/init_32.c | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c new file mode 100644 index 000000000000..730a5b177b1f --- /dev/null +++ b/arch/x86/mm/init_32.c @@ -0,0 +1,858 @@ +/* + * linux/arch/i386/mm/init.c + * + * Copyright (C) 1995 Linus Torvalds + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#include <linux/module.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/hugetlb.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/pfn.h> +#include <linux/poison.h> +#include <linux/bootmem.h> +#include <linux/slab.h> +#include <linux/proc_fs.h> +#include <linux/efi.h> +#include <linux/memory_hotplug.h> +#include <linux/initrd.h> +#include <linux/cpumask.h> + +#include <asm/processor.h> +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/dma.h> +#include <asm/fixmap.h> +#include <asm/e820.h> +#include <asm/apic.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> +#include <asm/sections.h> +#include <asm/paravirt.h> + +unsigned int __VMALLOC_RESERVE = 128 << 20; + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); +unsigned long highstart_pfn, highend_pfn; + +static int noinline do_test_wp_bit(void); + +/* + * Creates a middle page table and puts a pointer to it in the + * given global directory entry. This only returns the gd entry + * in non-PAE compilation mode, since the middle layer is folded. + */ +static pmd_t * __init one_md_table_init(pgd_t *pgd) +{ + pud_t *pud; + pmd_t *pmd_table; + +#ifdef CONFIG_X86_PAE + if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { + pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); + + paravirt_alloc_pd(__pa(pmd_table) >> PAGE_SHIFT); + set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); + pud = pud_offset(pgd, 0); + if (pmd_table != pmd_offset(pud, 0)) + BUG(); + } +#endif + pud = pud_offset(pgd, 0); + pmd_table = pmd_offset(pud, 0); + return pmd_table; +} + +/* + * Create a page table and place a pointer to it in a middle page + * directory entry. + */ +static pte_t * __init one_page_table_init(pmd_t *pmd) +{ + if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { + pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + + paravirt_alloc_pt(&init_mm, __pa(page_table) >> PAGE_SHIFT); + set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); + BUG_ON(page_table != pte_offset_kernel(pmd, 0)); + } + + return pte_offset_kernel(pmd, 0); +} + +/* + * This function initializes a certain range of kernel virtual memory + * with new bootmem page tables, everywhere page tables are missing in + * the given range. + */ + +/* + * NOTE: The pagetables are allocated contiguous on the physical space + * so we can cache the place of the first one and move around without + * checking the pgd every time. + */ +static void __init page_table_range_init (unsigned long start, unsigned long end, pgd_t *pgd_base) +{ + pgd_t *pgd; + pmd_t *pmd; + int pgd_idx, pmd_idx; + unsigned long vaddr; + + vaddr = start; + pgd_idx = pgd_index(vaddr); + pmd_idx = pmd_index(vaddr); + pgd = pgd_base + pgd_idx; + + for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { + pmd = one_md_table_init(pgd); + pmd = pmd + pmd_index(vaddr); + for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); pmd++, pmd_idx++) { + one_page_table_init(pmd); + + vaddr += PMD_SIZE; + } + pmd_idx = 0; + } +} + +static inline int is_kernel_text(unsigned long addr) +{ + if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) + return 1; + return 0; +} + +/* + * This maps the physical memory to kernel virtual address space, a total + * of max_low_pfn pages, by creating page tables starting from address + * PAGE_OFFSET. + */ +static void __init kernel_physical_mapping_init(pgd_t *pgd_base) +{ + unsigned long pfn; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + int pgd_idx, pmd_idx, pte_ofs; + + pgd_idx = pgd_index(PAGE_OFFSET); + pgd = pgd_base + pgd_idx; + pfn = 0; + + for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { + pmd = one_md_table_init(pgd); + if (pfn >= max_low_pfn) + continue; + for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) { + unsigned int address = pfn * PAGE_SIZE + PAGE_OFFSET; + + /* Map with big pages if possible, otherwise create normal page tables. */ + if (cpu_has_pse) { + unsigned int address2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1; + if (is_kernel_text(address) || is_kernel_text(address2)) + set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC)); + else + set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE)); + + pfn += PTRS_PER_PTE; + } else { + pte = one_page_table_init(pmd); + + for (pte_ofs = 0; + pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; + pte++, pfn++, pte_ofs++, address += PAGE_SIZE) { + if (is_kernel_text(address)) + set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); + else + set_pte(pte, pfn_pte(pfn, PAGE_KERNEL)); + } + } + } + } +} + +static inline int page_kills_ppro(unsigned long pagenr) +{ + if (pagenr >= 0x70000 && pagenr <= 0x7003F) + return 1; + return 0; +} + +int page_is_ram(unsigned long pagenr) +{ + int i; + unsigned long addr, end; + + if (efi_enabled) { + efi_memory_desc_t *md; + void *p; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if (!is_available_memory(md)) + continue; + addr = (md->phys_addr+PAGE_SIZE-1) >> PAGE_SHIFT; + end = (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT)) >> PAGE_SHIFT; + + if ((pagenr >= addr) && (pagenr < end)) + return 1; + } + return 0; + } + + for (i = 0; i < e820.nr_map; i++) { + + if (e820.map[i].type != E820_RAM) /* not usable memory */ + continue; + /* + * !!!FIXME!!! Some BIOSen report areas as RAM that + * are not. Notably the 640->1Mb area. We need a sanity + * check here. + */ + addr = (e820.map[i].addr+PAGE_SIZE-1) >> PAGE_SHIFT; + end = (e820.map[i].addr+e820.map[i].size) >> PAGE_SHIFT; + if ((pagenr >= addr) && (pagenr < end)) + return 1; + } + return 0; +} + +#ifdef CONFIG_HIGHMEM +pte_t *kmap_pte; +pgprot_t kmap_prot; + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), vaddr), (vaddr)), (vaddr)) + +static void __init kmap_init(void) +{ + unsigned long kmap_vstart; + + /* cache the first kmap pte */ + kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); + kmap_pte = kmap_get_fixmap_pte(kmap_vstart); + + kmap_prot = PAGE_KERNEL; +} + +static void __init permanent_kmaps_init(pgd_t *pgd_base) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + unsigned long vaddr; + + vaddr = PKMAP_BASE; + page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); + + pgd = swapper_pg_dir + pgd_index(vaddr); + pud = pud_offset(pgd, vaddr); + pmd = pmd_offset(pud, vaddr); + pte = pte_offset_kernel(pmd, vaddr); + pkmap_page_table = pte; +} + +static void __meminit free_new_highpage(struct page *page) +{ + init_page_count(page); + __free_page(page); + totalhigh_pages++; +} + +void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro) +{ + if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) { + ClearPageReserved(page); + free_new_highpage(page); + } else + SetPageReserved(page); +} + +static int __meminit add_one_highpage_hotplug(struct page *page, unsigned long pfn) +{ + free_new_highpage(page); + totalram_pages++; +#ifdef CONFIG_FLATMEM + max_mapnr = max(pfn, max_mapnr); +#endif + num_physpages++; + return 0; +} + +/* + * Not currently handling the NUMA case. + * Assuming single node and all memory that + * has been added dynamically that would be + * onlined here is in HIGHMEM + */ +void __meminit online_page(struct page *page) +{ + ClearPageReserved(page); + add_one_highpage_hotplug(page, page_to_pfn(page)); +} + + +#ifdef CONFIG_NUMA +extern void set_highmem_pages_init(int); +#else +static void __init set_highmem_pages_init(int bad_ppro) +{ + int pfn; + for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) + add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro); + totalram_pages += totalhigh_pages; +} +#endif /* CONFIG_FLATMEM */ + +#else +#define kmap_init() do { } while (0) +#define permanent_kmaps_init(pgd_base) do { } while (0) +#define set_highmem_pages_init(bad_ppro) do { } while (0) +#endif /* CONFIG_HIGHMEM */ + +unsigned long long __PAGE_KERNEL = _PAGE_KERNEL; +EXPORT_SYMBOL(__PAGE_KERNEL); +unsigned long long __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; + +#ifdef CONFIG_NUMA +extern void __init remap_numa_kva(void); +#else +#define remap_numa_kva() do {} while (0) +#endif + +void __init native_pagetable_setup_start(pgd_t *base) +{ +#ifdef CONFIG_X86_PAE + int i; + + /* + * Init entries of the first-level page table to the + * zero page, if they haven't already been set up. + * + * In a normal native boot, we'll be running on a + * pagetable rooted in swapper_pg_dir, but not in PAE + * mode, so this will end up clobbering the mappings + * for the lower 24Mbytes of the address space, + * without affecting the kernel address space. + */ + for (i = 0; i < USER_PTRS_PER_PGD; i++) + set_pgd(&base[i], + __pgd(__pa(empty_zero_page) | _PAGE_PRESENT)); + + /* Make sure kernel address space is empty so that a pagetable + will be allocated for it. */ + memset(&base[USER_PTRS_PER_PGD], 0, + KERNEL_PGD_PTRS * sizeof(pgd_t)); +#else + paravirt_alloc_pd(__pa(swapper_pg_dir) >> PAGE_SHIFT); +#endif +} + +void __init native_pagetable_setup_done(pgd_t *base) +{ +#ifdef CONFIG_X86_PAE + /* + * Add low memory identity-mappings - SMP needs it when + * starting up on an AP from real-mode. In the non-PAE + * case we already have these mappings through head.S. + * All user-space mappings are explicitly cleared after + * SMP startup. + */ + set_pgd(&base[0], base[USER_PTRS_PER_PGD]); +#endif +} + +/* + * Build a proper pagetable for the kernel mappings. Up until this + * point, we've been running on some set of pagetables constructed by + * the boot process. + * + * If we're booting on native hardware, this will be a pagetable + * constructed in arch/i386/kernel/head.S, and not running in PAE mode + * (even if we'll end up running in PAE). The root of the pagetable + * will be swapper_pg_dir. + * + * If we're booting paravirtualized under a hypervisor, then there are + * more options: we may already be running PAE, and the pagetable may + * or may not be based in swapper_pg_dir. In any case, + * paravirt_pagetable_setup_start() will set up swapper_pg_dir + * appropriately for the rest of the initialization to work. + * + * In general, pagetable_init() assumes that the pagetable may already + * be partially populated, and so it avoids stomping on any existing + * mappings. + */ +static void __init pagetable_init (void) +{ + unsigned long vaddr, end; + pgd_t *pgd_base = swapper_pg_dir; + + paravirt_pagetable_setup_start(pgd_base); + + /* Enable PSE if available */ + if (cpu_has_pse) + set_in_cr4(X86_CR4_PSE); + + /* Enable PGE if available */ + if (cpu_has_pge) { + set_in_cr4(X86_CR4_PGE); + __PAGE_KERNEL |= _PAGE_GLOBAL; + __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; + } + + kernel_physical_mapping_init(pgd_base); + remap_numa_kva(); + + /* + * Fixed mappings, only the page table structure has to be + * created - mappings will be set by set_fixmap(): + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; + end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; + page_table_range_init(vaddr, end, pgd_base); + + permanent_kmaps_init(pgd_base); + + paravirt_pagetable_setup_done(pgd_base); +} + +#if defined(CONFIG_HIBERNATION) || defined(CONFIG_ACPI) +/* + * Swap suspend & friends need this for resume because things like the intel-agp + * driver might have split up a kernel 4MB mapping. + */ +char __nosavedata swsusp_pg_dir[PAGE_SIZE] + __attribute__ ((aligned (PAGE_SIZE))); + +static inline void save_pg_dir(void) +{ + memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); +} +#else +static inline void save_pg_dir(void) +{ +} +#endif + +void zap_low_mappings (void) +{ + int i; + + save_pg_dir(); + + /* + * Zap initial low-memory mappings. + * + * Note that "pgd_clear()" doesn't do it for + * us, because pgd_clear() is a no-op on i386. + */ + for (i = 0; i < USER_PTRS_PER_PGD; i++) +#ifdef CONFIG_X86_PAE + set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); +#else + set_pgd(swapper_pg_dir+i, __pgd(0)); +#endif + flush_tlb_all(); +} + +int nx_enabled = 0; + +#ifdef CONFIG_X86_PAE + +static int disable_nx __initdata = 0; +u64 __supported_pte_mask __read_mostly = ~_PAGE_NX; +EXPORT_SYMBOL_GPL(__supported_pte_mask); + +/* + * noexec = on|off + * + * Control non executable mappings. + * + * on Enable + * off Disable + */ +static int __init noexec_setup(char *str) +{ + if (!str || !strcmp(str, "on")) { + if (cpu_has_nx) { + __supported_pte_mask |= _PAGE_NX; + disable_nx = 0; + } + } else if (!strcmp(str,"off")) { + disable_nx = 1; + __supported_pte_mask &= ~_PAGE_NX; + } else + return -EINVAL; + + return 0; +} +early_param("noexec", noexec_setup); + +static void __init set_nx(void) +{ + unsigned int v[4], l, h; + + if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { + cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); + if ((v[3] & (1 << 20)) && !disable_nx) { + rdmsr(MSR_EFER, l, h); + l |= EFER_NX; + wrmsr(MSR_EFER, l, h); + nx_enabled = 1; + __supported_pte_mask |= _PAGE_NX; + } + } +} + +/* + * Enables/disables executability of a given kernel page and + * returns the previous setting. + */ +int __init set_kernel_exec(unsigned long vaddr, int enable) +{ + pte_t *pte; + int ret = 1; + + if (!nx_enabled) + goto out; + + pte = lookup_address(vaddr); + BUG_ON(!pte); + + if (!pte_exec_kernel(*pte)) + ret = 0; + + if (enable) + pte->pte_high &= ~(1 << (_PAGE_BIT_NX - 32)); + else + pte->pte_high |= 1 << (_PAGE_BIT_NX - 32); + pte_update_defer(&init_mm, vaddr, pte); + __flush_tlb_all(); +out: + return ret; +} + +#endif + +/* + * paging_init() sets up the page tables - note that the first 8MB are + * already mapped by head.S. + * + * This routines also unmaps the page at virtual kernel address 0, so + * that we can trap those pesky NULL-reference errors in the kernel. + */ +void __init paging_init(void) +{ +#ifdef CONFIG_X86_PAE + set_nx(); + if (nx_enabled) + printk("NX (Execute Disable) protection: active\n"); +#endif + + pagetable_init(); + + load_cr3(swapper_pg_dir); + +#ifdef CONFIG_X86_PAE + /* + * We will bail out later - printk doesn't work right now so + * the user would just see a hanging kernel. + */ + if (cpu_has_pae) + set_in_cr4(X86_CR4_PAE); +#endif + __flush_tlb_all(); + + kmap_init(); +} + +/* + * Test if the WP bit works in supervisor mode. It isn't supported on 386's + * and also on some strange 486's (NexGen etc.). All 586+'s are OK. This + * used to involve black magic jumps to work around some nasty CPU bugs, + * but fortunately the switch to using exceptions got rid of all that. + */ + +static void __init test_wp_bit(void) +{ + printk("Checking if this processor honours the WP bit even in supervisor mode... "); + + /* Any page-aligned address will do, the test is non-destructive */ + __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); + boot_cpu_data.wp_works_ok = do_test_wp_bit(); + clear_fixmap(FIX_WP_TEST); + + if (!boot_cpu_data.wp_works_ok) { + printk("No.\n"); +#ifdef CONFIG_X86_WP_WORKS_OK + panic("This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); +#endif + } else { + printk("Ok.\n"); + } +} + +static struct kcore_list kcore_mem, kcore_vmalloc; + +void __init mem_init(void) +{ + extern int ppro_with_ram_bug(void); + int codesize, reservedpages, datasize, initsize; + int tmp; + int bad_ppro; + +#ifdef CONFIG_FLATMEM + BUG_ON(!mem_map); +#endif + + bad_ppro = ppro_with_ram_bug(); + +#ifdef CONFIG_HIGHMEM + /* check that fixmap and pkmap do not overlap */ + if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) { + printk(KERN_ERR "fixmap and kmap areas overlap - this will crash\n"); + printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n", + PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, FIXADDR_START); + BUG(); + } +#endif + + /* this will put all low memory onto the freelists */ + totalram_pages += free_all_bootmem(); + + reservedpages = 0; + for (tmp = 0; tmp < max_low_pfn; tmp++) + /* + * Only count reserved RAM pages + */ + if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) + reservedpages++; + + set_highmem_pages_init(bad_ppro); + + codesize = (unsigned long) &_etext - (unsigned long) &_text; + datasize = (unsigned long) &_edata - (unsigned long) &_etext; + initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; + + kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); + kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, + VMALLOC_END-VMALLOC_START); + + printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n", + (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), + num_physpages << (PAGE_SHIFT-10), + codesize >> 10, + reservedpages << (PAGE_SHIFT-10), + datasize >> 10, + initsize >> 10, + (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) + ); + +#if 1 /* double-sanity-check paranoia */ + printk("virtual kernel memory layout:\n" + " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#endif + " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" + " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" + " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", + FIXADDR_START, FIXADDR_TOP, + (FIXADDR_TOP - FIXADDR_START) >> 10, + +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, + (LAST_PKMAP*PAGE_SIZE) >> 10, +#endif + + VMALLOC_START, VMALLOC_END, + (VMALLOC_END - VMALLOC_START) >> 20, + + (unsigned long)__va(0), (unsigned long)high_memory, + ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, + + (unsigned long)&__init_begin, (unsigned long)&__init_end, + ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10, + + (unsigned long)&_etext, (unsigned long)&_edata, + ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, + + (unsigned long)&_text, (unsigned long)&_etext, + ((unsigned long)&_etext - (unsigned long)&_text) >> 10); + +#ifdef CONFIG_HIGHMEM + BUG_ON(PKMAP_BASE+LAST_PKMAP*PAGE_SIZE > FIXADDR_START); + BUG_ON(VMALLOC_END > PKMAP_BASE); +#endif + BUG_ON(VMALLOC_START > VMALLOC_END); + BUG_ON((unsigned long)high_memory > VMALLOC_START); +#endif /* double-sanity-check paranoia */ + +#ifdef CONFIG_X86_PAE + if (!cpu_has_pae) + panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!"); +#endif + if (boot_cpu_data.wp_works_ok < 0) + test_wp_bit(); + + /* + * Subtle. SMP is doing it's boot stuff late (because it has to + * fork idle threads) - but it also needs low mappings for the + * protected-mode entry to work. We zap these entries only after + * the WP-bit has been tested. + */ +#ifndef CONFIG_SMP + zap_low_mappings(); +#endif +} + +#ifdef CONFIG_MEMORY_HOTPLUG +int arch_add_memory(int nid, u64 start, u64 size) +{ + struct pglist_data *pgdata = NODE_DATA(nid); + struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; + unsigned long start_pfn = start >> PAGE_SHIFT; + unsigned long nr_pages = size >> PAGE_SHIFT; + + return __add_pages(zone, start_pfn, nr_pages); +} + +int remove_memory(u64 start, u64 size) +{ + return -EINVAL; +} +EXPORT_SYMBOL_GPL(remove_memory); +#endif + +struct kmem_cache *pmd_cache; + +void __init pgtable_cache_init(void) +{ + size_t pgd_size = PTRS_PER_PGD*sizeof(pgd_t); + + if (PTRS_PER_PMD > 1) { + pmd_cache = kmem_cache_create("pmd", + PTRS_PER_PMD*sizeof(pmd_t), + PTRS_PER_PMD*sizeof(pmd_t), + SLAB_PANIC, + pmd_ctor); + if (!SHARED_KERNEL_PMD) { + /* If we're in PAE mode and have a non-shared + kernel pmd, then the pgd size must be a + page size. This is because the pgd_list + links through the page structure, so there + can only be one pgd per page for this to + work. */ + pgd_size = PAGE_SIZE; + } + } +} + +/* + * This function cannot be __init, since exceptions don't work in that + * section. Put this after the callers, so that it cannot be inlined. + */ +static int noinline do_test_wp_bit(void) +{ + char tmp_reg; + int flag; + + __asm__ __volatile__( + " movb %0,%1 \n" + "1: movb %1,%0 \n" + " xorl %2,%2 \n" + "2: \n" + ".section __ex_table,\"a\"\n" + " .align 4 \n" + " .long 1b,2b \n" + ".previous \n" + :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), + "=q" (tmp_reg), + "=r" (flag) + :"2" (1) + :"memory"); + + return flag; +} + +#ifdef CONFIG_DEBUG_RODATA + +void mark_rodata_ro(void) +{ + unsigned long start = PFN_ALIGN(_text); + unsigned long size = PFN_ALIGN(_etext) - start; + +#ifndef CONFIG_KPROBES +#ifdef CONFIG_HOTPLUG_CPU + /* It must still be possible to apply SMP alternatives. */ + if (num_possible_cpus() <= 1) +#endif + { + change_page_attr(virt_to_page(start), + size >> PAGE_SHIFT, PAGE_KERNEL_RX); + printk("Write protecting the kernel text: %luk\n", size >> 10); + } +#endif + start += size; + size = (unsigned long)__end_rodata - start; + change_page_attr(virt_to_page(start), + size >> PAGE_SHIFT, PAGE_KERNEL_RO); + printk("Write protecting the kernel read-only data: %luk\n", + size >> 10); + + /* + * change_page_attr() requires a global_flush_tlb() call after it. + * We do this after the printk so that if something went wrong in the + * change, the printk gets out at least to give a better debug hint + * of who is the culprit. + */ + global_flush_tlb(); +} +#endif + +void free_init_pages(char *what, unsigned long begin, unsigned long end) +{ + unsigned long addr; + + for (addr = begin; addr < end; addr += PAGE_SIZE) { + ClearPageReserved(virt_to_page(addr)); + init_page_count(virt_to_page(addr)); + memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); + free_page(addr); + totalram_pages++; + } + printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); +} + +void free_initmem(void) +{ + free_init_pages("unused kernel memory", + (unsigned long)(&__init_begin), + (unsigned long)(&__init_end)); +} + +#ifdef CONFIG_BLK_DEV_INITRD +void free_initrd_mem(unsigned long start, unsigned long end) +{ + free_init_pages("initrd memory", start, end); +} +#endif + |